Process of making briquets from zinc ores and material containing zinc.



' taining Zinc,

such briquets commercially practicable process which will .tion, theparticles of said material dered coherent to a high degree. Briquets anera onnren OTTO vKIPPIEI, OE, OSNABRTTCK; GERMANY, ASSIGNOR T0 GENERALBRIQUETTING COMPANY, OF NEW YORK,

N. Y., A CORPORATION OF MAINE.

PROCESS OF MAKING BRIQUETS FROM ZINC OBES AND MATERIAL CONTAINING ZINCLlfiSAhIll.

No Drawing.

To all whom it may concern:

Be it known that I, OTTO KIPPE, a citizen of the German Empire, and aresident of Osnabriick, Germany, have invented anew, useful, andImproved Process of Making Briquets from Zinc Ores and Material Conofwhich the following is a specification.

In the production of spelter from zinc ores or the like by means of theknown reduction and distillation processes, especially the recent methodby which the. zinc ores are smelted in the electric furnace, theso-called zinc dust or blue powder is given off in large amounts as awaste by-product. Moreover,

in the refining of raw zinc or spelter, in the smelting of old spelterand in zincage or galvanizing processes, large amounts of waste in theform of zinc ash or Zinc trimmings are produced. These waste products,which consist for the most part of a mixture of zinc oxid and finelydivided metallic ZlIlC, of division renders them generally unsuitablefor smelting operations.

The present invention contemplates the utilization of this fine materialin the production of briquets suitable for smelting, and the object ofthe invention isto produce by a technically simple and hereinafter beset forth.

The basis of my mvention may be saidto be the discovery that when theabove rereferred to finely divided zinc containing material is moistenedwith a dilute salt solucan be made in this way without the necessity offoreign binding means and, moreover, they possessgreat strength and arein every waysuitable for smelting and this is true whether the briquetconsists mainly of zinc waste or whether it is composed mainly of zincores or the like and contains a relatively small proportion of zincwaste. My process is, therefore, suitable not only for preparing zincwaste briquets but also for briqueting finely divided zinc'ores,sufficient zinc byproduct being added in the latter case so that thewhole mass is rendered coherent. If pure zinc dust is moistened withpure water and then pressed into briquets, the

ing accompanied by the evolution of heat,

Specification of Letters Patent.

are of great value, but their fineness are ren- Patented Jan, 118, 1916.

Application filed November 19, 1914: Serial No. 872,890.

fractures will occur and the briquets shortly become whollydisintegrated. But if there is added to the mixing water a small amount,say 5; to 2%, of a soluble salt, such as for example, the chlori'd orsulfate of magnesium, calcium, iron or zinc (electroly.tes),or even the,free acids instead of the salts, the briquets give off heat and theirparticles become bound together so as to form within a few hours veryhard stones. If the waste material, as is usually the case with zinctrimmings, already contains small amounts of these salts, a furtheraddition of salt solution may not be necessary or may be neces' saryonly to a slight degree. Instead of the pure salt solution there can beadded successfully substances which in themselves contain such salts, asfor example, roasted zinc blende or pyrite cinder.. It is alsopermissible to incorporate with the zinc containing material thereducing materials ordinarily used in smelting, as anthracites, coke andthe like. I

The briqueting process is itself ,extremely simple. The material of thekind set forth is placed in a mixing machine together with reducingsubstances and the like, if desired, and is thoroughly mixed togethertherein in the presence of the water necessary for the compressingoperation and the salt solution, when necessary; after mixing, thematerial is pressed to. briquets by means of suitable press and thebriquets are then stored for hardening. Their particles quickly becomecoherent, heat being evolved meanwhile, and the briquets are soon readyfor smelting. The peculiar and extraordinary high binding or coheringpower of these zinc containing materials, such as zinc dust, zinc ashand the like is of utility not only for producing briquets consistingprimarily of such materials, but also for producing briquets of zincores and the like, in which case the zinc waste materials may be addedto the ores in suflicient amount to serve only to bind the ore particlestogether. Zinc ores and the like, such as are ordinarily available forsmelting, are generally very finely divided and a briqueting processsuitable for preparing said materials and fine ores for smeltingoperations is of great value. The above by-product materials form anindustrially. successful binding means for zine ores and the like and isof especial value for such use-because it is itself rich in zincandtherefore does not serve, as other binding materials do, as anadulterant of the ore; moreover the briqueting process is extremelysimple.

The zinc ores to be briqueted are mixed with the zinc containingby-product such as zinc dust (of which 8 to 10% is sufficient) in asimple mixing machine, in the presence of sufficient moisture andof therequisite percentage of the salt (preferably in diluted state). Thismixture -is then pressed in an ordinary briqueting press. If the ores tobe briqueted, as is the case, for example, with roasted zinc blende,already contain the" soluble salt in the form of zinc sulfate, calciumsulfate, etc., a special addition of salt is, generally speaking,unnecessary. There can be mixed with the ore at the same time whateverreducing agents may be necessary, such as ground coke or anthracite, andany other material required for subsequent smelting operations. Thebriquets evolve heat and become hard in a short time if they are left tostand in the air; they possess strength and tenacity to a high degreeand are ready for smelting without further treatment.

It is to be understood that besides this new binding means of zinccontaining material there can be used in addition thereto any well knownbinding means when the latter contains soluble salts, as is the case forexample with magnesia cement, cellulose-liquor and molasses. Moreover,the briquets, as well as the mixture, can be sub-- jected to a treatmentwith steam and gases, such as is often employed in briqueting processes.

The peculiar and high binding powers of the zinc containing by-productmaterial, as zinc dust, zinc ash, etc., in the presence of a catalyzer;and likewise the whole small amounts of salt is apparently due to thefact that in these'substances there are present very fine particles ofmetallic zinc which are transformed by the water and the oxygen of theair into zinc hydroxid which intimately cements the substances to bebound together. The slight amount of salt serves in this processapparently only as an accelerator and can therefore be termedproceeding. can be termed catalysis since the small amount of salt isnot present in stoichiometric, proportions with respect to the productformed.

I claim: 1. The hereindescribed process of producing briquets fromfinely divided zinc byproduct material which consists in setting upbinding conditions in said material by moisteningsaid material with aliquid containing a chemically reactive dissolved salt,

then compressing saidmoistened mass and evaporating the solvent, leavingthe dry salt distributed in the mass without cooperating in thecoherence of the mass.

2. The hereindescribed zinc-containing briquet comprising finely dividedzinc byproduct containing material, the particles of said material beingbound together to form a hard, coherent mass, and a relatively smallproportion of a water-soluble salt distributed throughout said mass asan ingredient which is inert with respect to the coherence of theparticles.

In testimony whereof, I have hereunto set my hand in-the presence of twosubscribing witnesses.

. OTTO KIPPE.

Witnessesz.

WILHELM STRUP, FREDERICK-HOYERMANN.

